Preheat Your Oven: Start by preheating your oven to 350°F (175°C). Line 2-3 baking sheets with parchment paper.

Mix Dry Ingredients: In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set it aside.

Cream Butter and Sugar: In the bowl of a stand mixer (or use a hand mixer), beat together the softened butter and granulated sugar on medium speed until light and fluffy, about 1-2 minutes.

Add Wet Ingredients: Crack the large egg into the mixture along with vanilla extract. Beat until well combined, roughly 30 seconds.

Combine Mixtures: Gradually add the dry ingredients to the butter mixture in two parts, mixing on low speed each time. Avoid overmixing.

Fold in Sprinkles: Gently fold in the Christmas jimmies sprinkles until evenly distributed.

Shape the Cookies: Use a 3-Tablespoon cookie scoop to portion out the dough and roll each scoop into a ball. Place them on the baking sheets with 2 inches of space between them.

Flatten the Cookie Balls: Slightly flatten each dough ball using your fingers or the bottom of a glass, keeping them at least ½-inch thick.

Bake the Cookies: Bake for 9-11 minutes until the edges are set and the tops are soft.

Cool the Cookies: Allow the cookies to cool on the baking sheets for about 5 minutes, then transfer to a wire rack to cool completely.

Make the Frosting: In a clean stand mixer bowl, use the whisk attachment to combine the cream cheese and salted butter on low speed until smooth.

Add Vanilla and Salt: Mix in 2 tsp of vanilla extract and ⅛ tsp of salt on low speed.

Incorporate Powdered Sugar: Gradually add sifted powdered sugar in three parts, beating on low speed until combined.

Whip in Heavy Cream: Slowly drizzle in very cold heavy cream, whisking on low until stiff peaks form, about 1-1½ minutes.

Frost the Cookies: Use a piping bag to pipe frosting in a spiral pattern over each cookie, or spread with a spatula.

Decorate: Sprinkle additional Christmas sprinkles over the frosting just before serving.